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TRY & TRY U WILL BE SUCCESS
Fundamentals Of Networking
SANJAY HIRANI
Semester: 4th
Branch:MCA
Fundamentals of Networking
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CH-1 INTRODUCTION TO COMPUTER NETWORK
1) Disadvantage of Layering?
 Reduced Speed and Performance
 Increased Memory Usage
2) The TCP/IP & OSI layering Models.
 The OSI Layering mechanism was designed by Open System
interconnection
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CH-2 NETWORK FUNDAMENTALS
2.1)
2.2)
Network Categories
 Networks can be categorized based on their scope, Connection type,
Communication mechanism, and usage important Fundamentals related
to networks.
2.1.1) Division Based on Scope
2.1.1.1) Personal Area Networks (PAN)
2.1.1.2) Local Area Networks (LAN)
2.1.1.3) Metropolitan Area Networks (MAN
2.1.1.4) Wide Area Networks (WAN)
2.1.1.5) Internetworks
2.1.2) Division Based on Connection
2.1.2.1) Wired Networks
2.1.2.2) Wireless Networks
2.1.3) Division Based on Communication Type
2.1.3.1) Broadcast Network
2.1.3.2) Point - to - Point Networks
2.1.4) Division Based on Usage
2.1.4.1) Home Networks
2.1.4.2) Sensor Networks
The Protocols
2.2.1)
2.2.2)
2.2.3)
2.2.4)
2.3)
the Standardization Bodies
Connection and Protocol
Connectionless and Connection-Oriented Protocols
layers and Protocols
Application of Computer Networks
2.3.1) Home Networking Application
2.3.2) Mobile Networking Application
2.3.3) Wireless Networking Application
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2.4)
Network Components
2.4.1) the Network Interface Card
2.4.2) Cable for Wired Connection
2.4.3) Frequency band For Wireless Transmission
2.4.4) the Servers and the Nodes
2.5.5) Interconnecting Devices
 Hub
 Switch
 Repeater
 Bridge
 Router
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CH-3 DATA COMMUNICATION FUNDAMENTALS
3.1) Analog and Digital Transmission
3.4.1) Introduction to Transmission
3.4.2) Analog Transmission
3.4.3) Digital Transmission
3.2) Modulation
3.2.1) Amplitude Modulation
3.2.2) Frequency Modulation
3.2.3) Phase Modulation
3.3) Analog & Digital Signal
3.3.1) Analog Signal
3.3.2) Digital Signal
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CH-4 The Physical layer
1) The Duties of Physical Layer
1.1) Machine Port Level Addressing
1.2) Transferring Bits
1.3) Synchronization the Sender & Receiver
1.4) Multiplexing Multiple Data Streams
1.5) Inappropriateness of FDM & TDM for Bursty data
1.6) The Electromagnetic Spectrum
1.7) Radio Waves
1.8) Microwaves
2) Wired Physical Layer
2.1) the UTP (Unshielded Twisted Pair) Cable
2.2) Fiber Optic Cables
2.3) the Total Internal Reflection Principle
2.4) Design of Fiber Cables
2.5) Sending & Receiving Devices
3) Wireless Physical Layer
3.1) Hidden & Exposed System
3.2) Hidden & Exposed Station Solution (RTS & CTS)
3.3) Components of the Wireless System
3.4) Antennas
3.5) Access Points
3.6) Wireless LAN
3.7) the 802.11 Standard
3.8) Ad-hoc & Infrastructure Modes
3.9) 802.11 Physical Layer
3.10) Wireless Communication using Satellite
4) Three Different Orbits
4.1) GEO- Geosynchronous Earth Orbit
4.2) LEO-Lower Earth Orbit
4.3) MEO- Medium Earth Orbit
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CH-5 The Data Link layer
1. The Duties of Data Link Layer
1.1) the No Monopoly Idea & Framing
1.2) Framing Techniques
 Framing using Byte and Stuff using Byte Stuffing
 Framing by Flag Byte and Bit Stuffing
 Framing by Using Illegal Combinations
 Character Count with Other Methods
2. Error Detection & Error Correction
2.1) Checksum (Detection & Correction)
2.2) CRC (Cyclic Redundancy Check) (Detection)
2.3) Modulo-2 Arithmetic – LRC (Detection)
3. The Protocols
3.1) the Sender & Receiver Concept
3.2) the Acknowledgement
3.3) Timers & the Time Out Event
3.4) the Sending & Receiving windows
3.5) the Sequence & Acknowledgement Numbers
3.6) Retransmission
3.7) Duplicate Frames
3.8) Go Back N
3.9) Selective Repeat
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CH-6 The Medium Access Sublayer
1) Introduction The Medium Access Sublayer
1.1) Shared Channel Concept
1.2) Collision Detection & Avoidance
1.3) Channel Acquisition issues
1.4) Ad-hoc & Infrastructure Modes
2) Wired MAC layer
2.1) Prerequisites to Ethernet, ALOHA and Slotted ALOHA
2.2) the Ethernet
2.1.1) Classic Ethernet
2.1.2) Ethernet Technology
2.1.3) Cascaded Star Topology
2.1.4) Frame Structure
2.1.5) Using Switch Instead of Hubs
2.1.6) The Binary Exponential Back-off Algorithm
2.1.7) Limitations of CSMA/CD
2.3) Fast Ethernet
2.4) Gigabit Ethernet
2.5) Virtual LAN
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CH-7 The Network Layer
1) Duties Of Network layer
1.1) Routing
1.2) Accounting
1.3) Receive Service from the Data Link layer
1.4) Provide Service to the Transport layer
1.5) Global Machine Level Addresing
1.5.1) Classful Addressing
1.5.2) The Dotted Decimal Notation
1.5.3) Classless Addressing
1.5.4) Unique Address Requirement
1.5.5) Network Address Translation
1.5.6) The Real Solution, IPv6
1.6) Multiplexing and Demultiplexing Multiple Transport layer
Connections
1.7) Multiplexing and Demultiplexing Multiple Transport layer
Connections
2) Routing Algorithms
2.1) Requirements of a Good Routing Algorithms
 Dynamism and Flexibility
 Performance
 Issues in router’s Performance
 Functions of a Router
 Lookup
 Switching
 Queuing
 Robustness
2.2) Internal & External Routing Algorithms
2.3) Distance Vector Routing
 Construction of Routing Tables
 The Count –to-Infinity Problem
 Solution Count –to-Infinity Problem
 Problem with count-to-infinity
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2.4) Link State Routing
 Finding Neighbours & delay
 Sequence Number and Age Fields
 Routing Table Construction
 The Optimality Principle
2.5) Routing in MANet
 No special Purposes Routers
 No fixed topology
 Best path Assumptions
 Power Requirement
 Security issues
 Ad-hoc On-demand Distance Vector
 Route Discovery Operation
 Route Maintenance
2.6) Border Gateway Protocol
 BGP & DV
 Path vector Routing
 No Count-to-infinity
 Complexity
 Impact of Business relationship
 The BGP operation
 Local Preference
 Avoiding False Alarms
 Check the Willingness to be an Intermediary
 Hot Potato
 Interior Routing
3) Congestion Control Algorithms
o Admission Control
o Prevention of Congested Routes
o Global Synchronization & Random Early Discard
o Jitter Control
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CH-8 The Transport Layer
1) Duties of the Transport Layer
 Retransmission
 Adapted retransmission time according to load
 Ordered Delivery
 Optimum Utilization of bandwidth
 Flow Control
 Real-Time Delivery
 Quality of Delivery
1.1) Multiplexing Demultiplexing and Port Numbers
1.2) Service to the Application Layer
1.3) Shortcomings of transport Layers of the Internet
 End to end Security
 End to End Specified quality of Service
 Isochronous Property
 Additional Security measures
1.4) Process-level Addressing
1.5) Providing End to end Solutions
 Flow Control
 Managing Multiple Connections Dynamically
 Timer Management
 Retransmission, RTT, and Timeout Calculations
 Timers
 Connection Establishment
 Retransmission
 Delayed ACK
 Persist
 Keepalive
 Fin-wait-2
 Time-Wait
2) Connection Management at the Transport Layer
2.1) Delayed Duplicates
 Time of reach the destination is variable
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 A delayed segment can be assumed lost
 ACKs can also be delayed
 Problems caused by delayed Duplicates
 A unique sequence number for each segment
 TCP Sequence numbers
 Size of Sequence number field
 Keep a track of obsolete sequence numbers
 What if the machine goes down?
 Choose a better initial sequence number
 Clock rate and speed of sending
 Desirable properties of a clock
 Delayed duplicates and connection establishment
2.2) Connection Establishment
 Identifying duplicate CRs and ACKs
 Assigning unique Connection IDs
 Limiting the segment lifetime
2.3) The Three-way Handshake
2.4) Connection Establishment in TCP
2.5) The Connection Release
 Symmetric and asymmetric connection close
 The Two-army Problem
3) Congestion Control
3.1) Detecting Congestions
 Implicit Method
 Explicit Method
3.2) Reacting to Congestion using RED (Random Early Discard)
 Tail drop and RED
 Dropping packets before the queue become full
 Determining the value of p
3.3) Fast Recovery MDCA & AIMD
3.4) Flow Control
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CH-9 The Application Layer
1) Domain Name System
1.1) The Domain Namespaces
 Advantages of Hierarchy
 The Distributed Database
 Search Mechanism and name Resolution
 The Zone
1.2) The Registration Process
1.3) The Name Servers
1.4) Resource Records
1.5) Different Types of Resource Records
1.6) Dynamic DNS
 The DNSSes
 DNS Poisoning
2) World Wide Web
2.1) The HTTP Query and Response
2.2) The Structure Of The Query Response
2.3) Other Method to Query the Server
2.4) Persistent Connection HTPP 1.1
 The Persist Connection
 Pipelining
2.5) Cookies
2.6) Session Variables
2.7) The Condition Download
2.8) Proxies as Intermediaries
2.9) Dynamic Web
 Server Side
 Client Side
3) Bluetooth
3.1) Bluetooth architecture
o Pairing
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3.2) Bluetooth Application
3.3) Bluetooth Profile
o Bluetooth Protocol Stack
3.4) Bluetooth Radio layer
3.5) Bluetooth Baseband Layer
3.6) Bluetooth L2CAP layer
3.7) Bluetooth Frame Structure
3.8) Bluetooth pairing process
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KEYWORDS
1) ATM- Asynchronous Transfer Mode
2) SMTP- Simple mail Transfer protocol
3) TCP/IP- Transmission Control Protocol/ Internet Protocol
4) OSI- Open System Interconnection
5) RFC- Recommendation For Comments
6) GUI- Graphical User Interface
7) NIC- Network Interface Card
8) IEEE- Institute of Electrical and Electronics Engineers
9) UDP- User Datagram Protocol
10) MANets- Mobile Ad hoc Networks
11) FDM- Frequency Division Multiplexing
12) TDM- Time Division Multiplexing
13) QAM- Quadrature Amplitude Modulation
14) ADSL- Asymmetric Digital Subscriber Line
15) OFDM- Orthogonal Frequency Division Multiplexing
16) CDMA- Code Division Multiple Access
17) ISM-Industrial Scientific & Medical
18) FSO-Free Space Optics
19) CTS- Clear to Send
20) DSL- Digital Subscriber Line
21) RTS- Request to Send
22) BSS- Basic Services Set
23) DSS- Distributed Services Set
24) EIFS- Extended interframe Spacing
25) SIFS- Small interframe Spacing
26) PCF- Point Coordinated Functioning
27) DCF- Distributed Coordinated Functioning
28) LLC- logical Link Control
29) ECN- Explicit Congestion Notification
30) FEC- Forward Equivalence Class
31) ICMP- Internet Control Message Protocol
32) CRC- Cyclic Redundancy Check
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GTU SHORT QUESTION
PAPER-1 (15-05-2012)
1) Distributed System
 A Distributed System Consists of a Collection of autonomous Computers,
Connected through a network and Distribution middleware, which enables
computers to coordinate their activities and to share the resource of the
System, so that users perceive as a single, integrated computing facility.
2) Flow Control
 The Data Link Layer deals with two entities directly connected to each
other. There is no restriction on somebody being a sender and somebody
else being a receiver.
 E.g: The First case involves downloading songs from the internet to a
mobile phone.
3) Harmonic
 A harmonic is a signal or wave whose frequency is an integral (wholenumber) multiple of the frequency of some reference signal or wave.
The term can also refer to the ratio of the frequency of such a signal or
wave to the frequency of the reference signal or wave.
4) Asynchronous Digital Subscriber Line
 ADSL is a technology for transmitting digital information at a high
bandwidth on existing phone lines to homes and businesses.
ADSL is asymmetric in that in uses most of the channel to transmit
downstream to the user and only a small part to receive information from
the user.
5) Stop and Wait
 Stop-n-wait (sometimes known as “positive acknowledgement with
retransmission”) is the fundamental technique to provide reliable transfer
under unreliable packet deleivery systems
6) Selective Repeat
 When the receiver window is large enough to hold more than one frames
This technique is known as Selective Repeat
 The Receiver now has a large buffer which can accommodate multiple out
of order frames.
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7) Four Service Classes in 802.16
 Unsolicited grant service(UGS)
 Real-Time Polling Service(RTPS)
 Non-Real Time polling Service(NRTPS)
 Best effort service(BE)
8) Replay Attack
 A replay attack is a from of network attack in which a valid data
transmission is maliciously or fraudulently repeated or delayed
9) Flag Byte
 Each frame starts and with special bytes: flag bytes. Two consecutive flag
bytes indicate end of frame and beginning on new frame.
10) Admission Control
 Admission Control is validation process in communication systems where a
check is performed before a connection is established to see if current
resources are sufficient for the proposed connection
11) POP3 Server
 In the simplest implementations of POP3, the server really does maintain a
collection of text files one for each e-mail account. When a message
arrives , the PPO3 server simply appends it to the bottom of the recipient’s
file
12) Privacy Amplification
 The transformation from the original one-time pad to different one that
reduces Trudy’s knowledge is called privacy amplification
13) Home application Example
 Computers, TV Connected to the internet by cable, DSL, Wireless, etc.
14) Example of Frequency Division Multiplexing
 Radio and Television transmission
15) Error Correcting Code
 Include enough redundancy to detect and correct errors.
16) Example Piggy Backing
 A person uses their neighbor’s wi-fi without their permission
17) Hidden Station Problem
 You must have noticed that both the problems are due to single reason.
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 Whenever the sender senses the channel it senses its surrounding
Receiver surrounding for any activity.
 A busy surrounding at the sender and a free Surrounding at the receiver
generates the Exposed Station Problem.
18) Example Delayed Duplicate
 Sorting the Disk files
19) Example Substitution Cipher
 Attack becomes DWWDFN
20) Dividing networking stacks in layers
 In OSI model, a networking system was divided into layers. Within each
layer, one or more entities implement its functionality, each entity
interacted directly only with the layer immediately beneath it, and
provided facilities for use by the layer above it.
21) Active and Passive repeater
 Active repeaters feed power as well as converting the week signal into its
original form passive repeaters act as assort of a reflector only.
22) List four business needs of a network
 Flexibility/ Scalability
 Functionality/Speed
 Manageability
 Security
23) List four home requirement of a network
 Modem
 Residential gateway
 Network bridge
 Network Hub/Switch
24) Write one reason for home networks no gaining popularity as they should
 One reason for home networks no gaining popularity as they should is
Network is too slow.
25) Name any two types of wireless networks prevalent in the market
1) Flying LAN
2) Individual mobile Computers
26) Write the difference between peer to peer vs. client server model
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 The difference between peer to peer vs. client server model is the fact that
a peer to peer network has no central server. Within a peer to peer
network all the computers are interconnected and can communicate, but
each one stores its own files and runs its own programs and applications
27) Differentiate between broadcast and point to point networks
Broadcast networks
1) Broadcast Networks uses LAN
Full mesh WAN
Point to Point Networks
1) Point to point Network uses
PPP, HDLC, partial mesh WAN
2) Broadcast means you sent
digital signals to any device
connected to a networks
3) Point to point means send
digital signals from a specific
point to a specific point(Identify
by IP address or MAC address)
28) Write two reasons why OSI model and TCP/IP model succeeded
 OSI did not take off is because it was a complete set of specifications that
was never subjected to any real implementations worth mentioning.
 The OSI model is may be complete and too complex. The gap between the
concrete use(implementations) and the model is sometimes significant
indeed, few programs can use or wrongly use the 7 layers of the model:
the session and presentations layers are hardly used an contrary the data
link and networks layers are often split into several sub-layers.
29) DMT: Discrete Multi Tone
30) List two types of frames needed by 802.16
 A generic frame
 A bandwidth request frame
31) Write any two reasons for introducing 802.16 even when 802.16 was round and
successful
 802.16 included mobility (Latest Standard)
 It proved useful in case of calamities
32) Write the amount of bandwidth offered by fast Ethernet
 The amount of bandwidth offered by fast Ethernet is 10 Mbps
33) ARQ: Automatic Repeat request
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PAPER-2 (16-05-2011)
1) What is the need for MIME?
MIME was needed to overcome the limitations of SMTP mentioned belo:
SMTP can not transfer executable files and binary objects
SMTP services may reject mails having size greater than a certain size
SMTP cannot handle non-textual data such as pictures , images, and video
2) What is the need for DNS in the Internet?
 DNS automatically converts the names we type in our
web browser address bar to IP address of web servers
hosting those sites
 DNS implements a distributed database to store this
name and address information for all public hosts on
the Internet
3) Mention uses of a computer network.
 Use of Computer Networks
1) Communication and Access to Information
2) Resource Sharing
3) Centralized Support and Administration
4) What is meant by : a) WAN b) PAN
WAN (Wide Area Network) spans a large geometric area, such as a state, province a
country.
 WANs often multiple smaller networks, such as local area network(LANs) or
MANs
PAN: A Personnel area networks is a computer organized around an individual
person.
 Personal area networks typically involve a mobile computer, a cell phone
and/or a computing device such a PDA
5. Differentiate between half duplex and full duplex channel.
 Half Duplex is used to describe communication where only one side can talk at a
time
 Full duplex is used to describe communication where both side are able to send
and receive data at the same time.
6. What is the major difference between a hub and a switch?
 A Hub is a networking device that allows one to connect multiple PCs to a single
network
 Switch is a computer networking device that connects network segments
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7. What is meant by security by obscurity?
 Security Through Obscurity(STO) is the belief that s system of any sort can be
secure so long as nobody outside of its implementation group is allowed to find
out anything about its internal mechanisms Hiding account passwords in binary
files or script with the presumption that “nobody will ever find it” is a prime case
of STO.
8. Differentiate between symmetric and asymmetric ciphers.
 In a symmetric, the key that deciphers the cipher text is the same as (or can be
easily derived from) the key encipher the clear text. This key is often referred to
as the secret key
 In an asymmetric cipher uses two keys: one keys that is kept secret and known to
only one person (the private key) and another key that is public and available to
everyone the two key are mathematically interrelated, but it’s impossible it drive
one key from the other.
9. Differentiate between routing process and forwarding process.
 Routing process is the process by which the forwarding table is built and
maintained
 Forwarding process is the process of moving packets input to output
11. What is the major drawback of Single Bit Parity check method for error detection?
 The major disadvantage of this method is that it is able to detect burst error if
number of bits change are even i.e. if 2,4,6,8..etc
12. What is the use of acknowledgement timer in data link layer protocols?
 The use of acknowledgement timer in data link layer protocols is to resend
frames that don’t produce an ACK when sending a frame, schedule a timer to
expire at some time after the ACK should have been returned
13. What is meant by Attenuation with respect to signals?
 In computer networking, attenuation is a loss of signal strength measured in
decibels Attenuation occurs on network foe several reasons.
 Range: Both wireless and wired transmissions gradually dissipate in strength over
longer reaches
 Interference: on wireless networks, radio interference or physical obstruction like
walls also dampen communication signals
 Wire size: on wired networks, thinner wires suffer from higher(more) attenuation
than thicker wires
14. Differentiate between flow control and congestion control.
 Congestion Control basically states that a networks device can transmit only a
certain number of packets and cannot add more packets to a network until an
acknowledgement is received
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 Flow control works by refusing new connections until congestion is resolved
15. Briefly explain any two forms of E-Commerce
 Forms of E-Commerce
The various forms of E-Commerce are as follows:
 Business to business E-Commerce (B2B Ecommerce)
 Business to Consumer E-Commerce (B2C Ecommerce)
 Consumer to Business E-Commerce(C2B Ecommerce)
 Consumer to Consumer E-commerce(C2c Ecommerce)
PAPER-5(07-01-2013)
1) Fill in the blanks.
I. A technique called piggybacking is used to improve the efficiency of the
bidirectional protocols.
II. In Go-Back-N ARQ protocol, we can send several frames before receiving
acknowledgements, improving the efficiency of transmission.
III. Protocols in which stations listen for a carrier and act accordingly are
Called Carrier sense protocols.
VI. MAC Sub Layer is the basic access method in wireless LANs; stations
contend with each other to get access to channel.
VII. In CDMA each station is assigned a unique m bit code called
Chip Sequence.
2) FHSS: Frequency Hopping Spread Spectrum
PAPER-6(09-12-2013)
1. How numbers of required check / redundant bits (r) are decided
for a given data bits of size (m) in Hamming Code?
1. What is the drawback of Manchester Encoding technique?
 The Drawback of Manchester Encoding technique is that the Manchester
encoded signal consumes more bandwidth than the original signal.
2. What is frame bursting in Gigabit Ethernet?
 Frame bursting a sender to transmit a concatenated sequence of multiple
frames in a single transmission
4. What is Station keeping in satellite communication?
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 The effects of solar, lunar, and planetary gravity tend to move them away from
their assigned orbit slots and orientations, an effects countered by on-board
rocket motors. This fine-tuning activity is called station keeping
3. Define the term cryptanalysis.
 The art of breaking ciphers is called Cryptanalysis
4. What is the usefulness of timer in data communication?
 The timer is set to expire after an interval long enough for the frame to reach the
destination, be processed there, and have the acknowledgement propagate back
to the Sender.
5. Explain following three Domain Resource Records’ types.
(a) SOA, (b) CNAME and (c) MX
Resource records
 A DNS Zone database is made up of a collection of resource records. Each
resource records specifies information about a particular object.
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